Core A, The International skeletal Dysplasia Registry (ISDR) was established 35 years ago and currently has over 14,700 cases in a secure, web-accessible, computerized database with an anonymized code for each ndividual. The Registry is the largest resource in the world for clinical and research material on the skeletal dysplasias and serves as the backbone of the research program. The materials include clinical information, radiographs, fixed and frozen chondro-osseous tissue samples, histology slides, electron micrographs, cultured fibroblasts and chondrocytes, lymphoblastoid cell lines, and DMA. The materials obtained by the Registry are extensively used by all the Projects as well as by numerous other collaborators. Radiographic and chondro-osseous morphological findings are encoded in the database in a searchable format for rapid identification of cases with similar findings. Cases entered into the Registry include patients seen in our Short Stature Clinics as well as cases submitted from around the world. The Specific Aims of this Core include: 1) Expansionof the Registry;2). Cell culture, isolation of nucleic acids, and distribution of samples; and 3). Enhancement of the Registry database.